Near-Infrared Nano-Optogenetic Activation of Cancer Immunotherapy via Engineered Bacteria

Living therapeutics: Precision diagnosis and therapy with engineered bacteria

Bacteria-based therapy has emerged as a promising strategy for cancer treatment, offering the potential for targeted tumor delivery, immune activation, and modulation of the tumor microenvironment. However, the unpredictable behavior, safety concerns, and limited efficacy of wild-type bacteria pose significant challenges to their clinical translation. Recent advancements in synthetic biology and chemical engineering have enabled the development of precisely engineered bacterial platforms with enhanced controllability, targeted delivery, and reduced toxicity. This review summarize the current progress of engineered bacteria in cancer therapy. We first introduce the theoretical underpinnings and key advantages of bacterial therapies in cancer. Subsequently, we delve into the applications of genetic engineering and chemical modification techniques to enhance their therapeutic potential. Finally, we address critical challenges and future prospects, with a focus on improving safety and efficacy. This review aims to stimulate further research and provide valuable insights into the development of engineered bacterial therapies for precision oncology.

Engineered Probiotics-Based Biohybrid-Driven Tumor Metabolic Remodeling To Boost Tumor Photoimmunotherapy

Bioengineered probiotics enable new opportunities to address abnormal cancer metabolism and suppressive immune-environment interactions for improved therapeutic susceptibility. Here, Escherichia coli Nissle 1917 (EcN) was constructed to convert ammonia into l-arginine continuously and was further modified with polydopamine (PDA) to form living biotherapeutic argEcN@P for enhanced colorectal cancer eradication. Benefiting from the movement of EcN, argEcN@P could colonize and penetrate deep in tumors through hypoxia targeting and increase the intratumoral l-arginine concentrations. Upon near-infrared light (NIR) irradiation, heating induced by PDA could ablate tumor cells efficiently and release tumor antigens, which induce immunogenic cell death (ICD). More interestingly, argEcN@P remarkably promotes differentiation into M1-like macrophages in tumor tissues, inhibiting primary, distant tumor growth by inducing potent adaptive antitumor immunity. More importantly, argEcN@P treatment efficiently prevented postoperative tumor recurrence by inducing long-term immune memory. Taken together, this platform based on bioengineered probiotics provides a promising strategy for tumor metabolic reprogramming sensitized photothermal immunotherapy in deep tumors.

Recent Advances in Spatiotemporal Manipulation of Engineered Bacteria for Precision Cancer Therapy

Solid tumours possess a hypoxic and immunosuppressive microenvironment, presenting a significant challenge to anticancer treatments. Certain anaerobic microorganisms thrive in this setting, rendering them promising candidates for targeted antitumour therapy delivery. In contrast to traditional nanodrug delivery systems, bacterial-based drug delivery systems can be engineered to produce and secrete therapeutics without the need for intricate post-purification or protective delivery methods. Nevertheless, bacteria can potentially migrate beyond their intended niche, causing off-target drug release and substantial toxicity to healthy tissues. Consequently, to enhance the effectiveness of cancer treatments while minimizing side effects, it is essential to precisely manipulate bacteria for accurate and controlled drug delivery directly to the tumour site. This can be achieved by employing inducible or repressible systems that allow for precise regulation of gene expression at specific times and locations. Ideally, engineering bacteria capable of rapidly and precisely transitioning between "on" and "off" states as required will enable them to recognize and react to targeted stimuli. While various techniques such as optical, magnetic, acoustic, and hyperbaric oxygen micromanipulation have been developed for the manipulation of particles or cells, each technique boasts its unique set of pros and cons. This review article provides an updated overview of the recent progress in the spatiotemporal control of engineered bacteria via these methods and discusses the benefits and constraints of each approach.

Self-luminous nanoengineered bacteria with the sustained release of interleukin 2 as an in situ vaccine for enhanced cancer immunotherapy

Bacteria-based in situ vaccination (ISV) has emerged as an effective therapeutic approach by activating anti-tumor immunity. However, inducing immunogenic cell death (ICD) and promoting effector T cell activation remain critical challenges in clinical applications of bacteria-based ISV. Here, we have developed a tumor microenvironment-activated nano-hybrid engineered bacterium as ISV. It was engineered with a blue-light response module (EL222) and self-luminous luminal hyaluronic acid (LHA) nanoparticles. Our study demonstrates that LHA generates local blue light stimulated by hydrogen peroxide, non-invasively activating the engineered Escherichia coli to produce IL-2. The engineered bacteria serve as an immunological adjuvant, promoting dendritic cell maturation, synergistically promoting T cell infiltration, and ultimately triggering a comprehensive activation of the immune system. Furthermore, when combined with the immune checkpoint inhibitor anti-PD-L1, this approach further effectively enhances cancer immunotherapy. Our results provide new strategies and promising prospects for the development of bacteria-based ISV immunotherapy. STATEMENT OF SIGNIFICANCE: This study developed a tumor microenvironment-activated nano-hybrid engineered bacteria (Ec-mIL2@LHA) as in situ vaccine for enhanced cancer immunotherapy. The LHA in bacterial vaccine non-invasively generated blue light upon stimulation by hydrogen peroxide of TME, leading to the sustained release of low-dose IL2 by engineered bacteria. In vitro and in vivo studies have demonstrated the bacterial in situ vaccine induced the immunogenic cell death and promote maturation of dendritic cells, ultimately triggering a comprehensive activation of anti-tumor immunity. After combination with anti-PD-L1, the bacterial in situ vaccine further effectively enhance cancer immunotherapy and inhibit metastasis. We provide a promising strategy to amplify antitumor immune effects by an engineered bacterial vaccine, showing potential clinical applications.

Ultrasound-Activated Precise Sono-Immunotherapy for Breast Cancer with Reduced Pulmonary Fibrosis

Immune checkpoint inhibitors have demonstrated remarkable efficacy across various cancer types. However, immune-related adverse events (irAEs) pose a significant challenge in immunotherapy, particularly the associated pneumonia as the primary adverse reaction, which can lead to irreversible pulmonary fibrosis. Additionally, monotherapy with programmed death ligand (PD-L1) inhibitors has shown limited effectiveness. Therefore, to improve the response rate of immunotherapy and reduce pulmonary fibrosis, this study designed and prepared an intelligent nanodrug based on dendritic mesoporous silica nanoparticles (DMSNs) loaded with a sono-sensitive agent protoporphyrin IX (PpIX). Additionally, a reactive oxygen species (ROS) sensitive linker is used to attach the immunotherapeutic drug PD-L1 inhibitor (aPD-L1) to DMSNs via covalent bonds. The external ultrasound (US) activates PpIX to generate ROS, which breaks the linker to release aPD-L1 to induce sonodynamic therapy (SDT) and immunotherapy. This sono-immnotherapy approach demonstrated excellent outcomes in tumor inhibition, eliciting immune responses, and reducing pulmonary fibrosis. Overall, this study offers a new, efficient, and safe method for breast cancer treatment, and expands the application of immunotherapy.

Upconversion Nanoparticle-Anchored Metal-Organic Framework Nanostructures for Remote-Controlled Cancer Optogenetic Therapy

Optogenetics, a revolutionary technique utilizing light-sensitive proteins to control cellular functions with high spatiotemporal precision, presents a promising avenue for disease treatment; however, its application in cancer therapy remains constrained by limited research. Herein, we introduce a pioneering strategy for remote-controlled optogenetic cancer therapy, synergistically merging optogenetics with ion therapy, which incorporates ion self-supply, in situ ion channel construction, and near-infrared (NIR) light-activated ion therapy, facilitating remote and noninvasive manipulation of cellular activities in deep tissues and living animals. We report the facile synthesis of water-dispersible upconversion nanoparticle (UCNP)-metal-organic framework (MOF) nanohybrids capable of effectively delivering plasmid DNA to cancer cells, thereby enabling the in situ expression of photoactivatable cation channels. The pH-responsive MOF components serve as a reservoir for metal cations, which are released in the acidic microenvironment of tumors, while the UCNP components function as remote-controlled transducers, converting near-infrared (NIR) light into visible light to activate the cation channels and allowing the cancer influx of released metal cations for ion therapy. The proposed remote-controlled cancer optogenetic therapy demonstrates its effectiveness across multiple tumor models, including subcutaneous colon tumors, subcutaneous breast tumors, and orthotopic breast tumors. This study represents a significant step toward the realization of optogenetics in clinics, with substantial potential for advancing cancer therapy.

Anti-PD-L1 Antibody Fragment Linked to Tumor-Targeting Lipid Nanoparticle Can Eliminate Cancer and Its Metastasis via Photoimmunotherapy

Effective cancer therapy aims to treat primary tumors and metastatic and recurrent cancer. Immune checkpoint blockade-mediated immunotherapy has shown promising effects against tumors; however, its efficacy in metastatic or recurrent cancer is limited. Here, based on the advantages of nanomedicine, lipid nanoparticles (LNPs) that can target tumors are synthesized for photothermal therapy (PTT) and immunotherapy to treat primary and metastatic recurrent cancer. These LNPs, termed piLNPs, are encapsulated with indocyanine green and incorporated with the antigen (Ag)-binding fragment of the anti-PD-L1 antibody for targeting tumors and immunotherapy. Intravenously injected piLNPs in 4T1 breast tumor-bearing BALB/c mice effectively target the 4T1 tumor and are suitable for performing PTT using a near-infrared laser. Moreover, lung metastatic 4T1 tumor growth is completely prevented in mice previously cured of the 4T1 breast tumor by piLNP treatment and rechallenged with lung 4T1 metastatic cancer. Blockage of the second challenged metastatic 4T1 breast cancer by piLNP is due to the activation of Ag-specific T cells. Cytotoxic T lymphocytes from piLNP-cured mice selectively attack 4T1 breast cancer cells. Therefore, piLNP can be used as a multifunctional breast cancer treatment composition that can target tumors, treat primary tumors, and prevent metastasis and recurrence.

Water-Dispersible and Biocompatible Polymer-Based Organic Upconversion Nanoparticles for Transdermal Delivery

Photomedicine, which utilizes light for therapeutic purposes, has several hurdles such as limited tissue penetration for short-wavelength light and inadequate deep tissue efficacy for long-wavelength light. Photon energy upconversion (UC) reveals promise in photomedicine because it enables the conversion of lower-energy photons into higher-energy photon. Lanthanide (Ln)-based inorganic UC system has been extensively studied but faces challenges, including high excitation laser power density, intrinsically subpar UC quantum efficiency, and potential biotoxicity. Recently, an organic-based triplet-triplet annihilation UC (TTA-UC) system has emerged as a novel UC system due to its prolonged emission lifetime upon low power laser excitation and exceptional UC quantum yield. In this study, we developed water-dispersible hyaluronic acid (HA)-conjugated polycaprolactone (PCL) nanoparticles loaded with TTA-UC chromophores (HA-PCL/UC NPs), which allow deeper tissue penetration by converting red light (635 nm) into blue light (470 nm) for noninvasive transdermal delivery. HA-PCL/UC NPs demonstrated a 1.6% high quantum yield in distilled water, improved cellular imaging in HeLa cells, and effectively penetrated the deep tissue of porcine skin, showing upconverted blue light. Our strategy holds significant potential as a next-generation noninvasive photomedicine platform for bioimaging, photo-triggered drug delivery, and photodynamic therapy, ultimately advancing targeted and effective therapeutic interventions.

The Rational Engineered Bacteria Based Biohybrid Living System for Tumor Therapy

Living therapy based on bacterial cells has gained increasing attention for their applications in tumor treatments. Bacterial cells can naturally target to tumor sites and active the innate immunological responses. The intrinsic advantages of bacteria attribute to the development of biohybrid living carriers for targeting delivery toward hypoxic environments. The rationally engineered bacterial cells integrate various functions to enhance the tumor therapy and reduce toxic side effects. In this review, the antitumor effects of bacteria and their application are discussed as living therapeutic agents across multiple antitumor platforms. The various kinds of bacteria used for cancer therapy are first introduced and demonstrated the mechanism of antitumor effects as well as the immunological effects. Additionally, this study focused on the genetically modified bacteria for the production of antitumor agents as living delivery system to treat cancer. The combination of living bacterial cells with functional nanomaterials is then discussed in the cancer treatments. In brief, the rational design of living therapy based on bacterial cells highlighted a rapid development in tumor therapy and pointed out the potentials in clinical applications.

In Vivo Optogenetics Based on Heavy Metal-Free Photon Upconversion Nanoparticles

Photon upconversion (UC) from red or near-infrared (NIR) light to blue light is promising for in vivo optogenetics. However, the examples of in vivo optogenetics have been limited to lanthanide inorganic UC nanoparticles, and there have been no examples of optogenetics without using heavy metals. Here the first example of in vivo optogenetics using biocompatible heavy metal-free TTA-UC nanoemulsions is shown. A new organic TADF sensitizer, a boron difluoride curcuminoid derivative modified with a bromo group, can promote intersystem crossing to the excited triplet state, significantly improving TTA-UC efficiency. The TTA-UC nanoparticles formed from biocompatible surfactants and methyl oleate acquire water dispersibility and remarkable oxygen tolerance. By combining with genome engineering technology using the blue light-responding photoactivatable Cre-recombinase (PA-Cre), TTA-UC nanoparticles promote Cre-reporter EGFP expression in neurons in vitro and in vivo. The results open new opportunities toward deep-tissue control of neural activities based on heavy metal-free fully organic UC systems.

Enhancing glioma treatment with 3D scaffolds laden with upconversion nanoparticles and temozolomide in orthotopic mouse model

Targeted drug delivery for primary brain tumors, particularly gliomas, is currently a promising approach to reduce patient relapse rates. The use of substitutable scaffolds, which enable the sustained release of clinically relevant doses of anticancer medications, offers the potential to decrease the toxic burden on the patient's organism while also enhancing their quality of life and overall survival. Upconversion nanoparticles (UCNPs) are being actively explored as promising agents for detection and monitoring of tumor growth, and as therapeutic agents that can provide isolated therapeutic effects and enhance standard chemotherapy. Our study is focused on the feasibility of constructing scaffolds using methacrylated hyaluronic acid with additional impregnation of UCNPs and the chemotherapeutic drug temozolomide (TMZ) for glioma treatment. The designed scaffolds have been demonstrated their efficacy as a drug and UCNPs delivery system for gliomas. Using the aggressive orthotopic glioma model in vivo, it was found that the scaffolds possess the capacity to ameliorate neurological disorders in mice. Moreover, upon intracranial co-implantation of the scaffolds and glioma cells, the constructs disintegrate into distinct segments, augmenting the release of UCNPs into the surrounding tissue and concurrently reducing postoperative damage to brain tissue. The use of TMZ in the scaffold composition contributed to restraining glioma development and the reduction of tumor invasiveness. Our findings unveil promising prospects for the application of photopolymerizable biocompatible scaffolds in the realm of neuro-oncology.

Nanomaterial combined engineered bacteria for intelligent tumor immunotherapy

Cancer remains the leading cause of human death worldwide. Compared to traditional therapies, tumor immunotherapy has received a lot of attention and research focus due to its potential to activate both innate and adaptive immunity, low toxicity to normal tissue, and long-term immune activity. However, its clinical effectiveness and large-scale application are limited due to the immunosuppression microenvironment, lack of spatiotemporal control, expensive cost, and long manufacturing time. Recently, nanomaterial combined engineered bacteria have emerged as a promising solution to the challenges of tumor immunotherapy, which offers spatiotemporal control, reversal of immunosuppression, and scalable production. Therefore, we summarize the latest research on nanomaterial-assisted engineered bacteria for precise tumor immunotherapies, including the cross-talk of nanomaterials and bacteria as well as their application in different immunotherapies. In addition, we further discuss the advantages and challenges of nanomaterial-engineered bacteria and their future prospects, inspiring more novel and intelligent tumor immunotherapy.

Spatiotemporal Delivery of Dual Nanobodies by Engineered Probiotics to Reverse Tumor Immunosuppression via Targeting Tumor-Derived Exosomes

The anti-PD-L1 and its bispecific antibodies have exhibited durable antitumor immunity but still elicit immunosuppression mainly caused by tumor-derived exosomes (TDEs), leading to difficulty in clinical transformation. Herein, engineered Escherichia coli Nissle 1917 (EcN) coexpressing anti-PD-L1 and anti-CD9 nanobodies (EcN-Nb) are developed and decorated with zinc-based metal-organic frameworks (MOFs) loaded with indocyanine green (ICG), to generate EcN-Nb-ZIF-8CHO-ICG (ENZC) for spatiotemporal lysis of bacteria for immunotherapy. The tumor-homing hybrid system can specifically release nanobodies in response to near-infrared (NIR) radiation, thereby targeting TDEs and changing their biological distribution, remodeling tumor-associated macrophages to M1 states, activating more effective and cytotoxic T lymphocytes, and finally, leading to the inhibition of tumor proliferation and metastasis. Altogether, the microfluidic-enabled MOF-modified engineered probiotics target TDEs and activate the antitumor immune response in a spatiotemporally manipulated manner, offering promising TDE-targeted immune therapy.

From pathogenesis to treatment: the impact of bacteria on cancer

The intricate relationship between cancer and bacteria has garnered increasing attention in recent years. While traditional cancer research has primarily focused on tumor cells and genetic mutations, emerging evidence highlights the significant role of microbial communities within the tumor microenvironment in cancer development and progression. This review aims to provide a comprehensive overview of the current understanding of the complex interplay between cancer and bacteria. We explore the diverse ways in which bacteria influence tumorigenesis and tumor behavior, discussing direct interactions between bacteria and tumor cells, their impact on tumor immunity, and the potential modulation of the tumor microenvironment. Additionally, we delve into the mechanisms through which bacterial metabolites and extracellular products May affect cancer pathways. By conducting a thorough analysis of the existing literature, we underscore the multifaceted and intricate relationship between bacteria and cancer. Understanding this complex interplay could pave the way for novel therapeutic approaches and preventive strategies in cancer treatment.

Light-Triggered PROTAC Nanoassemblies for Photodynamic IDO Proteolysis in Cancer Immunotherapy

While proteolysis-targeting chimeras (PROTACs) hold great potential for persistently reprogramming the immunosuppressive tumor microenvironment via targeted protein degradation, precisely activating them in tumor tissues and preventing uncontrolled proteolysis at off-target sites remain challenging. Herein, a light-triggered PROTAC nanoassembly (LPN) for photodynamic indoleamine 2,3-dioxygenase (IDO) proteolysis is reported. The LPN is derived from the self-assembly of prodrug conjugates, which comprise a PROTAC, cathepsin B-specific cleavable peptide linker, and photosensitizer, without any additional carrier materials. In colon tumor models, intravenously injected LPNs initially silence the activity of PROTACs and accumulate significantly in targeted tumor tissues due to an enhanced permeability and retention effect. Subsequently, the cancer biomarker cathepsin B begins to trigger the release of active PROTACs from the LPNs through enzymatic cleavage of the linkers. Upon light irradiation, tumor cells undergo immunogenic cell death induced by photodynamic therapy to promote the activation of effector T cells, while the continuous IDO degradation of PROTAC simultaneously blocks tryptophan metabolite-regulated regulatory-T-cell-mediated immunosuppression. Such LPN-mediated combinatorial photodynamic IDO proteolysis effectively inhibits tumor growth, metastasis, and recurrence. Collectively, this study presents a promising nanomedicine, designed to synergize PROTACs with other immunotherapeutic modalities, for more effective and safer cancer immunotherapy.

Harnessing and Mimicking Bacterial Features to Combat Cancer: From Living Entities to Artificial Mimicking Systems

Bacterial-derived micro-/nanomedicine has garnered considerable attention in anticancer therapy, owing to the unique natural features of bacteria, including specific targeting ability, immunogenic benefits, physicochemical modifiability, and biotechnological editability. Besides, bacterial components have also been explored as promising drug delivery vehicles. Harnessing these bacterial features, cutting-edge physicochemical and biotechnologies have been applied to attenuated tumor-targeting bacteria with unique properties or functions for potent and effective cancer treatment, including strategies of gene-editing and genetic circuits. Further, the advent of bacteria-inspired micro-/nanorobots and mimicking artificial systems has furnished fresh perspectives for formulating strategies for developing highly efficient drug delivery systems. Focusing on the unique natural features and advantages of bacteria, this review delves into advances in bacteria-derived drug delivery systems for anticancer treatment in recent years, which has experienced a process from living entities to artificial mimicking systems. Meanwhile, a summary of relative clinical trials is provided and primary challenges impeding their clinical application are discussed. Furthermore, future directions are suggested for bacteria-derived systems to combat cancer.

Functional nanotransducer-mediated wireless neural modulation techniques

Functional nanomaterials have emerged as versatile nanotransducers for wireless neural modulation because of their minimal invasion and high spatiotemporal resolution. The nanotransducers can convert external excitation sources (e.g. NIR light, x-rays, and magnetic fields) to visible light (or local heat) to activate optogenetic opsins and thermosensitive ion channels for neuromodulation. The present review provides insights into the fundamentals of the mostly used functional nanomaterials in wireless neuromodulation including upconversion nanoparticles, nanoscintillators, and magnetic nanoparticles. We further discussed the recent developments in design strategies of functional nanomaterials with enhanced energy conversion performance that have greatly expanded the field of neuromodulation. We summarized the applications of functional nanomaterials-mediated wireless neuromodulation techniques, including exciting/silencing neurons, modulating brain activity, controlling motor behaviors, and regulating peripheral organ function in mice. Finally, we discussed some key considerations in functional nanotransducer-mediated wireless neuromodulation along with the current challenges and future directions.

Engineering Microorganisms for Cancer Immunotherapy

Cancer immunotherapy presents a promising approach to fight against cancer by utilizing the immune system. Recently, engineered microorganisms have emerged as a potential strategy in cancer immunotherapy. These microorganisms, including bacteria and viruses, can be designed and modified using synthetic biology and genetic engineering techniques to target cancer cells and modulate the immune system. This review delves into various microorganism-based therapies for cancer immunotherapy, encompassing strategies for enhancing efficacy while ensuring safety and ethical considerations. The development of these therapies holds immense potential in offering innovative personalized treatments for cancer.

Nano-optogenetics for Disease Therapies

Optogenetic, known as the method of 21 centuries, combines optic and genetic engineering to precisely control photosensitive proteins for manipulation of a broad range of cellular functions, such as flux of ions, protein oligomerization and dissociation, cellular intercommunication, and so on. In this technique, light is conventionally delivered to targeted cells through optical fibers or micro light-emitting diodes, always suffering from high invasiveness, wide-field illumination facula, strong absorption, and scattering by nontargeted endogenous substance. Light-transducing nanomaterials with advantages of high spatiotemporal resolution, abundant wireless-excitation manners, and easy functionalization for recognition of specific cells, recently have been widely explored in the field of optogenetics; however, there remain a few challenges to restrain its clinical applications. This review summarized recent progress on light-responsive genetically encoded proteins and the myriad of activation strategies by use of light-transducing nanomaterials and their disease-treatment applications, which is expected for sparking helpful thought to push forward its preclinical and translational uses.

Nanomaterials modulate tumor-associated macrophages for the treatment of digestive system tumors

The treatment of digestive system tumors presents challenges, particularly in immunotherapy, owing to the advanced immune tolerance of the digestive system. Nanomaterials have emerged as a promising approach for addressing these challenges. They provide targeted drug delivery, enhanced permeability, high bioavailability, and low toxicity. Additionally, nanomaterials target immunosuppressive cells and reshape the tumor immune microenvironment (TIME). Among the various cells in the TIME, tumor-associated macrophages (TAMs) are the most abundant and play a crucial role in tumor progression. Therefore, investigating the modulation of TAMs by nanomaterials for the treatment of digestive system tumors is of great significance. Here, we present a comprehensive review of the utilization of nanomaterials to modulate TAMs for the treatment of gastric cancer, colorectal cancer, hepatocellular carcinoma, and pancreatic cancer. We also investigated the underlying mechanisms by which nanomaterials modulate TAMs to treat tumors in the digestive system. Furthermore, this review summarizes the role of macrophage-derived nanomaterials in the treatment of digestive system tumors. Overall, this research offers valuable insights into the development of nanomaterials tailored for the treatment of digestive system tumors.

Putting Hybrid Nanomaterials to Work for Biomedical Applications

Hybrid nanomaterials have found use in many biomedical applications. This article provides a comprehensive review of the principles, techniques, and recent advancements in the design and fabrication of hybrid nanomaterials for biomedicine. We begin with an introduction to the general concept of material hybridization, followed by a discussion of how this approach leads to materials with additional functionality and enhanced performance. We then highlight hybrid nanomaterials in the forms of nanostructures, nanocomposites, metal-organic frameworks, and biohybrids, including their fabrication methods. We also showcase the use of hybrid nanomaterials to advance biomedical engineering in the context of nanomedicine, regenerative medicine, diagnostics, theranostics, and biomanufacturing. Finally, we offer perspectives on challenges and opportunities.

Novel immunotherapies for breast cancer: Focus on 2023 findings

Immunotherapy has emerged as a revolutionary approach in cancer therapy, and recent advancements hold significant promise for breast cancer (BCa) management. Employing the patient's immune system to combat BCa has become a focal point in immunotherapeutic investigations. Strategies such as immune checkpoint inhibitors (ICIs), adoptive cell transfer (ACT), and targeting the tumor microenvironment (TME) have disclosed encouraging clinical outcomes. ICIs, particularly programmed cell death protein 1 (PD-1)/PD-L1 inhibitors, exhibit efficacy in specific BCa subtypes, including triple-negative BCa (TNBC) and human epidermal growth factor receptor 2 (HER2)-positive cancers. ACT approaches, including tumor-infiltrating lymphocytes (TILs) and chimeric antigen receptor (CAR) T-cell therapy, showed promising clinical outcomes in enhancing tumor recognition and elimination. Targeting the TME through immune agonists and oncolytic viruses signifies a burgeoning field of research. While challenges persist in patient selection, resistance mechanisms, and combination therapy optimization, these novel immunotherapies hold transformative potential for BCa treatment. Continued research and clinical trials are imperative to refine and implement these innovative approaches, paving the way for improved outcomes and revolutionizing the management of BCa. This review provides a concise overview of the latest immunotherapies (2023 studies) in BCa, highlighting their potential and current status.

Engineering the next generation of theranostic biomaterials with synthetic biology

Biomaterials have evolved from inert materials to responsive entities, playing a crucial role in disease diagnosis, treatment, and modeling. However, their advancement is hindered by limitations in chemical and mechanical approaches. Synthetic biology enabling the genetically reprograming of biological systems offers a new paradigm. It has achieved remarkable progresses in cell reprogramming, engineering designer cells for diverse applications. Synthetic biology also encompasses cell-free systems and rational design of biological molecules. This review focuses on the application of synthetic biology in theranostics, which boost rapid development of advanced biomaterials. We introduce key fundamental concepts of synthetic biology and highlight frontier applications thereof, aiming to explore the intersection of synthetic biology and biomaterials. This integration holds tremendous promise for advancing biomaterial engineering with programable complex functions.

Genetically engineered probiotics for an optical imaging-guided tumor photothermal therapy/immunotherapy

Bacteria-based cancer therapy (BCT) has been extensively investigated because of the tumor targeting and antitumor immunity activating abilities of bacteria over traditional nanodrugs, but their potential systemic toxicity poses a challenge. Therefore, it is important to visualize the precise localization and real-time distribution of bacteria in vivo to guide the treatment. Herein, biogenetically engineered Escherichia coli Nissle 1917 (EcN) were constructed to highly express tyrosinase to intracellularly generate cyanine 5-labeled melanin-like polymers (Cy5-Mel), thus endowing them with a bright fluorescence and an excellent photothermal performance upon NIR laser irradiation, thereby inducing the intense immunogenic death of tumor cells and release of tumor-associated antigens. Acting as adjuvants, bacteria can greatly stimulate the maturation of dendritic (DC) cells. The in vivo behaviors of these bacteria was monitored via noninvasive optical imaging when they were intravenously administrated to tumor-bearing mice. From this, NIR exposure on tumor sites was carried out at an appropriate time point to induce the damage to tumor cells and for the modulation of tumor immune microenvironments. Thus, via a simple bioengineering strategy, a promising bacteria-based theranostic platform was constructed for tumor treatment.

Optogenetic Neuromodulation in Inflammatory Pain

Inflammatory pain is one of the most prevalent forms of pain and negatively influences the quality of life. Neuromodulation has been an expanding field of pain medicine and is accepted by patients who have failed to respond to several conservative treatments. Despite its effectiveness, neuromodulation still lacks clinically robust evidence on inflammatory pain management. Optogenetics, which controls particular neurons or brain circuits with high spatiotemporal accuracy, has recently been an emerging area for inflammatory pain management and studying its mechanism. This review considers the fundamentals of optogenetics, including using opsins, targeting gene expression, and wavelength-specific light delivery techniques. The recent evidence on application and development of optogenetic neuromodulation in inflammatory pain is also summarised. The current limitations and challenges restricting the progression and clinical transformation of optogenetics in pain are addressed. Optogenetic neuromodulation in inflammatory pain has many potential targets, and developing strategies enabling clinical application is a desirable therapeutic approach and outcome.

Joining Forces: The Combined Application of Therapeutic Viruses and Nanomaterials in Cancer Therapy

Cancer, on a global scale, presents a monumental challenge to our healthcare systems, posing a significant threat to human health. Despite the considerable progress we have made in the diagnosis and treatment of cancer, realizing precision cancer therapy, reducing side effects, and enhancing efficacy remain daunting tasks. Fortunately, the emergence of therapeutic viruses and nanomaterials provides new possibilities for tackling these issues. Therapeutic viruses possess the ability to accurately locate and attack tumor cells, while nanomaterials serve as efficient drug carriers, delivering medication precisely to tumor tissues. The synergy of these two elements has led to a novel approach to cancer treatment-the combination of therapeutic viruses and nanomaterials. This advantageous combination has overcome the limitations associated with the side effects of oncolytic viruses and the insufficient tumoricidal capacity of nanomedicines, enabling the oncolytic viruses to more effectively breach the tumor's immune barrier. It focuses on the lesion site and even allows for real-time monitoring of the distribution of therapeutic viruses and drug release, achieving a synergistic effect. This article comprehensively explores the application of therapeutic viruses and nanomaterials in tumor treatment, dissecting their working mechanisms, and integrating the latest scientific advancements to predict future development trends. This approach, which combines viral therapy with the application of nanomaterials, represents an innovative and more effective treatment strategy, offering new perspectives in the field of tumor therapy.

Genetically engineered bacteria: a new frontier in targeted drug delivery

Genetically engineered bacteria (GEB) have shown significant promise to revolutionize modern medicine. These engineered bacteria with unique properties such as enhanced targeting, versatility, biofilm disruption, reduced drug resistance, self-amplification capabilities, and biodegradability represent a highly promising approach for targeted drug delivery and cancer theranostics. This innovative approach involves modifying bacterial strains to function as drug carriers, capable of delivering therapeutic agents directly to specific cells or tissues. Unlike synthetic drug delivery systems, GEB are inherently biodegradable and can be naturally eliminated from the body, reducing potential long-term side effects or complications associated with residual foreign constituents. However, several pivotal challenges such as safety and controllability need to be addressed. Researchers have explored novel tactics to improve their capabilities and overcome existing challenges, including synthetic biology tools (e.g., clustered regularly interspaced short palindromic repeats (CRISPR) and bioinformatics-driven design), microbiome engineering, combination therapies, immune system interaction, and biocontainment strategies. Because of the remarkable advantages and tangible progress in this field, GEB may emerge as vital tools in personalized medicine, providing precise and controlled drug delivery for various diseases (especially cancer). In this context, future directions include the integration of nanotechnology with GEB, the focus on microbiota-targeted therapies, the incorporation of programmable behaviors, the enhancement in immunotherapy treatments, and the discovery of non-medical applications. In this way, careful ethical considerations and regulatory frameworks are necessary for developing GEB-based systems for targeted drug delivery. By addressing safety concerns, ensuring informed consent, promoting equitable access, understanding long-term effects, mitigating dual-use risks, and fostering public engagement, these engineered bacteria can be employed as promising delivery vehicles in bio- and nanomedicine. In this review, recent advances related to the application of GEB in targeted drug delivery and cancer therapy are discussed, covering crucial challenging issues and future perspectives.

Advances in anti-tumor based on various anaerobic bacteria and their derivatives as drug vehicles

Cancer therapies, such as chemotherapy and radiotherapy, are often unsatisfactory due to several limitations, including drug resistance, inability to cross biological barriers, and toxic side effects on the body. These drawbacks underscore the need for alternative treatments that can overcome these challenges and provide more effective and safer options for cancer patients. In recent years, the use of live bacteria, engineered bacteria, or bacterial derivatives to deliver antitumor drugs to specific tumor sites for controlled release has emerged as a promising therapeutic tool. This approach offers several advantages over traditional cancer therapies, including targeted drug delivery and reduced toxicity to healthy tissues. Ongoing research in this field holds great potential for further developing more efficient and personalized cancer therapies, such as E. coli, Salmonella, Listeria, and bacterial derivatives like outer membrane vesicles (OMVs), which can serve as vehicles for drugs, therapeutic proteins, or antigens. In this review, we describe the advances, challenges, and future directions of research on using live bacteria or OMVs as carriers or components derived from bacteria of delivery systems for cancer therapy.

Nanoparticle-Based Photothermal Therapy for Breast Cancer Noninvasive Treatment

Rapid advancements in materials science and nanotechnology, intertwined with oncology, have positioned photothermal therapy (PTT) as a promising noninvasive treatment strategy for cancer. The breast's superficial anatomical location and aesthetic significance render breast cancer a particularly pertinent candidate for the clinical application of PTT following melanoma. This review comprehensively explores the research conducted on the various types of nanoparticles employed in PTT for breast cancer and elaborates on their specific roles and mechanisms of action. The integration of PTT with existing clinical therapies for breast cancer is scrutinized, underscoring its potential for synergistic outcomes. Additionally, the mechanisms underlying PTT and consequential modifications to the tumor microenvironment after treatment are elaborated from a medical perspective. Future research directions are suggested, with an emphasis on the development of integrative platforms that combine multiple therapeutic approaches and the optimization of nanoparticle synthesis for enhanced treatment efficacy. The goal is to push the boundaries of PTT toward a comprehensive, clinically applicable treatment for breast cancer.

Cancer phototherapy with nano-bacteria biohybrids

The utilization of light for therapeutic interventions, also known as phototherapy, has been extensively employed in the treatment of a wide range of illnesses, including cancer. Despite the benefits of its non-invasive nature, phototherapy still faces challenges pertaining to the delivery of phototherapeutic agents, phototoxicity, and light delivery. The incorporation of nanomaterials and bacteria in phototherapy has emerged as a promising approach that leverages the unique properties of each component. The resulting nano-bacteria biohybrids exhibit enhanced therapeutic efficacy when compared to either component individually. In this review, we summarize and discuss the various strategies for assembling nano-bacteria biohybrids and their applications in phototherapy. We provide a comprehensive overview of the properties and functionalities of nanomaterials and cells in the biohybrids. Notably, we highlight the roles of bacteria beyond their function as drug vehicles, particularly their capacity to produce bioactive molecules. Despite being in its early stage, the integration of photoelectric nanomaterials and genetically engineered bacteria holds promise as an effective biosystem for antitumor phototherapy. The utilization of nano-bacteria biohybrids in phototherapy is a promising avenue for future investigation, with the potential to enhance treatment outcomes for cancer patients.

Bacteria associated with glioma: a next wave in cancer treatment

Malignant gliomas occur more often in adults and may affect any part of the central nervous system (CNS). Although their results could be better, surgical excision, postoperative radiation and chemotherapy, and electric field therapy are today's mainstays of glioma care. However, bacteria can also exert anti-tumor effects via mechanisms such as immune regulation and bacterial toxins to promote apoptosis, inhibit angiogenesis, and rely on their natural characteristics to target the tumor microenvironment of hypoxia, low pH, high permeability, and immunosuppression. Tumor-targeted bacteria expressing anticancer medications will go to the cancer site, colonize the tumor, and then produce the therapeutic chemicals that kill the cancer cells. Targeting bacteria in cancer treatment has promising prospects. Rapid advances have been made in the study of bacterial treatment of tumors, including using bacterial outer membrane vesicles to load chemotherapy drugs or combine with nanomaterials to fight tumors, as well as the emergence of bacteria combined with chemotherapy, radiotherapy, and photothermal/photodynamic therapy. In this study, we look back at the previous years of research on bacteria-mediated glioma treatment and move forward to where we think it is headed.